The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 06, 1993
Filed:
Jan. 15, 1992
John C Gee, Aurora, IL (US);
Jeffrey I Rosenfeld, Schaumburg, IL (US);
Thomas M Bartos, Wheaton, IL (US);
Amoco Corporation, Chicago, IL (US);
Abstract
A process is disclosed for counter-current positive displacement of an aliphatic carboxylic acid of 1 to 5 carbon atoms from a filter cake of an aromatic polycarboxylic acid containing the aliphatic carboxylic acid wherein mother liquor retained by the aromatic polycarboxylic acid has a concentration of the aliphatic carboxylic acid of 5000 ppmw, or less, based upon weight of the aromatic polycarboxylic acid present. This method is useful for the manufacture of crude terephthalic acid which is used after purification for the preparation of polyesters used for the manufacture of fabrics, fibers and plastic bottles.